JPH01270214A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent characteristics of a capacitor from varying or deteriorating, and to improve reliability by sealing the opening of a case with fluorine rubber packing, and then coating the packing with thermosetting resin to seal the opening. CONSTITUTION:After the opening of a case 4 containing a capacitor element 3 is sealed with a fluorine rubber packing 8 having excellent heat resistance, the packing 8 is coated with thermosetting resin 10 to seal the opening of the case 4. Accordingly, since it is sealed with high airtightness and the packing 8 having excellent heat resistance is employed, it can endure against high temperature at the time of impregnating a melted organic semiconductor 5, the heat at the time of curing the resin 10 does not affect directly the semiconductor 5, thereby preventing an external appearance from deteriorating and a lead pitch from deforming. Thus, it can prevent characteristics of a capacitor from varying or deteriorating, and improve reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a solid electrolytic capacitor manufacturing method for manufacturing consumer or industrial solid electrolytic capacitors.

[Conventional technology]

Generally, when manufacturing solid electrolytic capacitors, aluminum and tantalum are used, as shown in Figure 6.

An anode lead (1) is bonded to an anode foil made of a chemically formed foil of a metal with valve action such as niobium, and an anode lead (1) is bonded to the anode foil.
The anode foil, one separator paper, the cathode foil and the other separator paper are polymerized and wound to form a capacitor element (31), and the capacitor element (31) is placed inside a cylindrical metal case (4) with a bottom. A capacitor element (31 is placed in case f4
The capacitor element (31) is impregnated with the organic semiconductor C51 inserted into the capacitor element (31) and melted, and the capacitor element (31) together with the case (4) is cooled to solidify the organic semiconductor C51. 6) A solid electrolytic capacitor (7) is manufactured by filling the inside of the case (41) and sealing the opening of the case (41).

However, in this case, the capacitor element (31) is housed in the case (4) containing the molten organic semiconductor (5),
When cooling the capacitor element (3) along with the case (41) to solidify the organic semiconductor (5), the organic semiconductor 151 may solidify while the capacitor element +31 is tilted as shown in FIG. In the case of sealing with synthetic resin (6),
This has the drawback of causing a defective appearance of the capacitor r71 and deformation of the lead pitch.

Furthermore, when sealing with the thermosetting resin (6), the organic semiconductor (5) and the thermosetting resin (6) are cured at high temperatures.
) may undergo a chemical reaction, resulting in a capacitor (
This leads to a decrease in the capacitance of capacitor [7] and an increase in leakage current, resulting in a disadvantage that the reliability of capacitor [7] decreases.

Therefore, Japanese Utility Model Application Publication No. 52-120939 (HQIG9
/10), the opening of the case may be sealed with an elastic sealing body such as a rubber seal, or
As described in Publication No. 38848 (HoIG 9/24), it has been considered that after sealing the opening of the case with an elastic sealing body, a resin is applied for reinforcement and the opening is double sealed. There is.

In this way, by sealing the opening of the υ case with the elastic sealing body, it is possible to prevent the capacitor element (31) from tilting as described above, thereby preventing appearance defects of the capacitor (7) and deformation of the lead pitch. In addition to being able to prevent thermosetting resin [
It is possible to prevent the reliability of the capacitor (7>) from decreasing due to the heat generated during curing of the capacitor (6).

[Problem to be solved by the invention]

However, using only an elastic sealing material such as a rubber seal is inferior to thermosetting resin in terms of airtightness, so the capacitor f
71 capacitance 9 equivalent series resistance (ESR).

There is a problem in that characteristics such as −δ and leakage current vary greatly.

Moreover, solid electrolytic capacitors do not have a strong self-repairing action like electrolytic capacitors, so when attaching the elastic sealing body to the capacitor element (31), external force is applied to the capacitor element +31, causing the anode of element +31 to By damaging the chemically formed foil, the E of the capacitor r7)
SR and leakage current may increase, leading to a decrease in yield.

In addition, in the case of double sealing using the above-mentioned elastic sealing body and resin, since it is possible to seal while maintaining high airtightness, it can be expected to have the effect of suppressing changes in the characteristics of the capacitor (7) as in the case of using only the above-mentioned elastic sealing body. However, depending on the materials of the elastic sealing body and the resin, there is a problem in that changes in characteristics and deterioration of the manufactured capacitor (7) cannot be sufficiently suppressed.

Therefore, the present invention has been made with the above-mentioned points in mind, and an object of the present invention is to prevent a decrease in reliability of a solid electrolytic capacitor.

[Means to solve the problem]

Next, means for achieving the above object will be explained using FIG. 1 which corresponds to an embodiment.

That is, a capacitor element (3) is formed by polymerizing and winding an anode foil made of a chemically formed foil of a metal having valve action such as aluminum, tantalum, or niobium, one separator paper, a cathode foil, and the other separator paper. A capacitor element (31) is impregnated with a molten organic semiconductor (5+), and the capacitor element (3) is housed in a bottomed cylindrical case +41,
In the method for manufacturing a solid electrolytic capacitor, the method includes manufacturing a solid electrolytic capacitor by sealing the opening of the case (41),
The present invention is characterized in that after the opening is sealed with a fluorine rubber gasket (8), thermosetting resin 1G is coated on the gasket (8) to seal the opening.

A capacitor element (3) is formed by polymerizing and winding an anode foil made of a chemically formed foil of a metal having a valve action such as aluminum, tantalum, niobium, separator paper on one side, cathode foil on the other hand, and separator paper on the other side; After attaching a fluorine-based rubber gasket (8) to the capacitor element A3), the capacitor element (3) is subjected to reconversion treatment 7, and the capacitor element +31 is impregnated with a molten organic semiconductor +51,
The capacitor element (31) may be housed in a cylindrical case with a bottom, and the opening of the case (4) may be sealed with the packing fl'il.

[Effect]

Therefore, according to the present invention, after the opening of the case (4) housing the capacitor element f3+ is sealed with a fluorine-based rubber gasket (8) having excellent heat resistance, the thermosetting resin 00 is placed over the rubber gasket +8. The opening of the case (41) is sealed with a coating, and compared to sealing with rubber gaskets or thermosetting resin alone, it is sealed with high airtightness, and has excellent heat resistance, and is also highly heat resistant. Due to its properties, it can withstand high temperatures during impregnation with molten organic semiconductor +51, and the heat during curing of thermosetting resin No. does not directly reach organic semiconductor 15+.
Not only is it possible to prevent appearance defects and deformation of the lead pitch of the solid electrolytic capacitor, but also changes and deterioration of the characteristics of the capacitor are prevented, and a decrease in the reliability of the solid electrolytic capacitor is prevented.

Furthermore, if the fluorine rubber gasket [8] is attached to the capacitor element (31) before the reconversion treatment of the capacitor element +31, the chemical foil of the capacitor element (31) will be damaged by the external force applied when the rubber gasket R81 is attached. However, since the damaged chemical foil is repaired by the subsequent re-forming treatment, there is no increase in the ESR or leakage current of the solid electrolytic capacitor, which is the case with conventional solid electrolytic capacitors, and a decrease in yield is prevented.

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 5 showing embodiments thereof.

First, FIG. 1 and FIG. 2 showing Example 1 will be explained. In FIG. 1, the same symbols as in FIG. 6 indicate the same or corresponding parts.

Now, as shown in Figure 1, aluminum, tantalum,
An anode lead (1) is bonded to an anode foil made of a chemically formed foil of a metal having valve action such as niobium, and a cathode lead (2) is bonded to the cathode foil.

One separator paper, the cathode foil, and the other separator paper are polymerized and wound to form a capacitor element +31.

Next, the organic semiconductor +
The capacitor element (3) containing and melting 51 and subjected to heat treatment is inserted into the case (4), and the rubber gasket +81 is fitted into the opening of the case (41), and the molten organic semiconductor +51 is inserted into the capacitor. The organic semiconductor (5) is impregnated into the element r31, the capacitor element (3) together with the case f41 is cooled, and the organic semiconductor (5) is solidified. 41
After sealing the opening of the case (4), a thermosetting resin aO made of epoxy resin is coated on the rubber packing 181 and cured, and the opening of the case (4) is sealed to manufacture a solid electrolytic capacitor.

By the way, in order to investigate changes in the characteristics of the solid electrolytic capacitor (hereinafter referred to as capacitor A) manufactured as described above, a high temperature load test was conducted at 125°C for 2000 hours, and the capacitance changes after 500, 1000 and 2000 hours were measured. The results of the measurements were as shown in Figure 2. For comparison, a solid electrolytic capacitor (hereinafter referred to as capacitor B) whose case opening was sealed only with thermosetting resin as shown in Figure 6, and A solid electrolytic capacitor (hereinafter referred to as capacitor C) whose case opening was sealed only with a fluorine-based rubber gasket was also subjected to the same high-temperature load test at <125°C, and the capacitance change was measured after 500, 1000, and 2000 hours. The results are also shown in Figure 2. However, the vertical axis in FIG. 2 indicates the ratio of the change in capacity after each measurement time period to the capacity before the start of the test.

In addition, each capacitor A subjected to this high temperature load test,
B, CO rating: 15wv 15%F Terrorism The fluorine-based rubber packing (8) was a fluorine-based rubber packing manufactured by Asahi Glass Co., Ltd. under the trade name ``Afras''.

As is clear from Fig. 2, capacitor A is
Compared to other capacitors B and C, there is almost no change in capacitance after 2000 hours, and the fluorine rubber gasket R8)
It can be seen that the double sealing by the thermosetting resin 110 and the thermosetting resin 110 makes it possible to prevent changes and deterioration of the characteristics of the capacitor.

This is because fluorine-based rubber gaskets have excellent heat resistance and are about 400 times better in gas barrier properties than silicone-based rubber gaskets, which also have high heat resistance. By doubly sealing the opening of the case R41 as shown in Fig. 1, compared to the case of sealing with a fluorine-based rubber gasket or a thermosetting resin alone, This is because the opening of the case r41 can be sealed with high airtightness, and the heat during curing of the thermosetting resin GO can be prevented from directly reaching the organic semiconductor (5). This makes it possible to prevent changes and deterioration in the characteristics of solid electrolytic capacitors.

Next, FIGS. 3 and 4 showing Example 2 will be explained.

In Fig. 3, the same symbols as in Fig. 1 indicate the same things, and the difference from Fig. 1 is that the capacitor element (3) is housed in the case (4) and the fluorine rubber gasket (8) is inserted into the opening of the case f41. The upper end of the case (4) is horizontally drawn, and the rubber gasket (8) is used to secure the case (4).
After sealing the opening of the case (4), the upper end of the case (4) is curled, and the case (4) is wrapped in a 7" cylindrical vinyl nullie.
(111), thermosetting resin GO made of epoxy resin was coated on the rubber gasket (8) inside the upper end of the sleeve 011 and cured, and the case (4) was sealed.

The solid electrolytic capacitor (hereinafter referred to as capacitor D) manufactured in this way was subjected to a high temperature no-load test at 125°C for 2 hours.
, as a result of measuring the leakage current after 2.0 hours, the fourth
For comparison, a solid electrolytic capacitor (hereinafter referred to as capacitor E) whose case opening is sealed only with thermosetting resin as shown in Fig. A no-load test was performed and the results were 0.5 and 1.0.
, the leakage current was measured after 2.0 hours had elapsed, and the results are also shown in FIG. However, rubber pads (8)
The above-mentioned "Afras" manufactured by Asahi Glass Co., Ltd. is used.

Note that the ratings of capacitors D and E used in this test are 1
The leakage current was measured 15 seconds after applying a voltage of 0WVIOμF and IOV.

As is clear from FIG. 4, the capacitor D is
Compared to Capacitor E, the leakage current after 2 hours has hardly changed from the initial value, and this is due to the same reason as Capacitor A in Example 1 described above, and it is possible to prevent changes and deterioration of the characteristics of the solid electrolytic capacitor. This is because it has become possible.

By the way, as Example 3, as shown in FIG.
Even if the thickness is reduced to the minimum value that can prevent the inclination in case [4] of No. 31, the same effect as in both of the above embodiments can be obtained.

Next, as Example 4, a solid electrolytic capacitor having the same structure as that shown in FIG. 1 except for the thermosetting resin flO and manufactured by the manufacturing procedure described below will be described. In addition, in the following description, FIG. 1 is referred to.

Connect the capacitor element (both leads of 31, lead bonne of f21 to the through hole (9) of the fluorine rubber gasket (8)
into the capacitor element (31), and then insert the rubber gasket (8) into the capacitor element (31
After the capacitor element (3) is reconstituted, the capacitor element (3) is inserted into the case (4) containing the melted organic semiconductor (5), and the rubber gasket (8) is inserted into the case (4). The capacitor element +31 is impregnated with the organic semiconductor (5), and then the case (
4) Cool down the capacitor element +31 and store the capacitor element (3) in the case (4).
The upper end of the case (4) is laterally drawn and the opening of the case (4) is sealed with a rubber gasket 48+ to produce a solid electrolytic capacitor.

And like this, fluorine rubber gasket +8+〇.

In order to investigate the effect on customization of capacitors due to the fact that they were installed on capacitor elements (3) prior to the reconstitution treatment of capacitor elements (31), eight solid electrolytic capacitors rated at 6WV 4.7 μF were assembled using the procedure described above. The initial values of capacitance tan δ, leakage current, F, and S R (equivalent series resistance) were measured for each of the capacitors N11l to H8 as shown in Table 1.However, in Table 1, ( indicates standard deviation.

(Table 1) Capacity and -δ are the values at 120H2 υ, leakage current is the value 10 seconds after applying a voltage of 16V, and F'
; S temperature is the value at 100 KHz, both are at room temperature (
20°C).

On the other hand, for comparison, fluorine rubber gasket (8)
Similarly, when the capacitor element (31) is installed after the reconversion treatment of the capacitor element (3), 15WV4.7
Table 2 shows the results of examining the characteristics of the μF rated capacitor 1-48.

(Table 2) Therefore, as is clear from the data in Table 11 and Table 2,
By attaching a fluorine rubber gasket fl'll to the capacitor element (3) before the reconversion treatment of the capacitor element (3), it is possible to suppress increases and variations in leakage current and ESR. It is noticeable in

If the fluorine-based rubber gasket (8) is attached to the capacitor element (3) before the reconstitution treatment of the capacitor element (31), the external force applied when the rubber gasket (8) is attached will be avoided, and the chemical conversion of the capacitor element (3) will be avoided. This is because even if the foil is damaged, the damaged chemically formed foil can be repaired by the next re-forming process, and as a result, it has become possible to suppress the increase and variation in leakage current and EAH, and improve yield. It is.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

The fluorine-based rubber gasket and thermosetting resin double seal the opening of the case, making it possible to seal the case with higher airtightness than when sealing with a rubber gasket or thermosetting resin alone. Furthermore, by using a fluorine-based rubber gasket with excellent heat resistance and barrier properties, it can withstand high temperatures during impregnation with molten organic semiconductors, and prevents heat during curing of thermosetting resin from directly reaching the organic semiconductors. This not only prevents appearance defects and deformation of the pitch of the solid electrolytic capacitor, but also prevents changes and deterioration of the characteristics of the capacitor, and prevents a decrease in the reliability of the solid electrolytic capacitor.

By attaching a fluorine-based rubber gasket to the capacitor element before the reconversion treatment of the capacitor element, even if the condensed foil of the capacitor element is damaged, the damaged chemical foil can be repaired by the next reconversion treatment. It is possible to prevent an increase in the ESR and leakage current of solid electrolytic capacitors such as solid electrolytic capacitors, and to improve yield.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the solid electrolytic capacitor manufacturing method of the present invention, FIGS. 1 and 2 show Example 1, FIG. 1 is a sectional view of the solid electrolytic capacitor, and FIG. The figure is a diagram of the relationship between time and capacity change in a high-temperature load test.
Figure 4 shows Example 2, Figure 3 is a cross-sectional view of the solid electrolytic capacitor, Figure 4 is a relationship between time and leakage current in a high temperature no-load test, and Figure 5 shows the solid electrolytic capacitor of Example 3. A sectional view of an electrolytic capacitor, FIG. 6 is a sectional view of a conventional example. 13)...Capacitor element, (4)...Case, (
5)...Organic semiconductor, j8)...Fluorine rubber gasket, flO...Thermosetting resin.

Claims (2)

[Claims] (1) A capacitor element is formed by polymerizing and winding an anode foil made of a chemically formed metal foil having a valve action such as aluminum, tantalum, or niobium, one separator paper, a cathode foil, and the other separator paper, and the capacitor element A method for manufacturing a solid electrolytic capacitor in which a solid electrolytic capacitor is manufactured by impregnating the capacitor element with a molten organic semiconductor, storing the capacitor element in a bottomed cylindrical case, and sealing the opening of the case, A method for producing a solid electrolytic capacitor, which comprises sealing the opening with a fluorine-based rubber packing, and then coating the packing with a thermosetting resin to seal the opening. (2) A capacitor element is formed by polymerizing and winding an anode foil made of a chemically formed foil of a metal having a valve action such as aluminum, tantalum, or niobium, one separator paper, a cathode foil, and the other separator paper; After attaching a fluorine-based rubber packing to the capacitor element, the capacitor element is reconstituted, the capacitor element is impregnated with a molten organic semiconductor, the capacitor element is housed in a cylindrical case with a bottom, and the packing is used to seal the case. A method for manufacturing a solid electrolytic capacitor, the method comprising: sealing an opening of a solid electrolytic capacitor.